Create the django_etesync app.

django_etesync/models.py

@@ -1,3 +1,78 @@
-from django.db import models
+# Copyright © 2017 Tom Hacohen
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, version 3.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
 
-# Create your models here.
+from django.db import models
+from django.conf import settings
+from django.core.validators import RegexValidator
+from django.utils.functional import cached_property
+
+
+UidValidator = RegexValidator(regex=r'[a-zA-Z0-9\-_=]{44}', message='Not a valid UID. Expected a 256bit base64url.')
+
+
+class Collection(models.Model):
+    uid = models.CharField(db_index=True, blank=False, null=False,
+                           max_length=44, validators=[UidValidator])
+    version = models.PositiveSmallIntegerField()
+    owner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
+
+    class Meta:
+        unique_together = ('uid', 'owner')
+
+    def __str__(self):
+        return self.uid
+
+
+class CollectionItem(models.Model):
+    uid = models.CharField(db_index=True, blank=False, null=False,
+                           max_length=44, validators=[UidValidator])
+    version = models.PositiveSmallIntegerField()
+    encryptionKey = models.BinaryField(editable=True, blank=False, null=False)
+    collection = models.ForeignKey(Collection, on_delete=models.CASCADE)
+
+    class Meta:
+        unique_together = ('uid', 'collection')
+
+    @cached_property
+    def content(self):
+        return self.snapshots.get(current=True)
+
+    def __str__(self):
+        return self.uid
+
+
+class CollectionItemSnapshot(models.Model):
+    item = models.ForeignKey(CollectionItem, related_name='snapshots', on_delete=models.CASCADE)
+    current = models.BooleanField(default=True)
+    chunkHmac = models.CharField(max_length=50, blank=False, null=False)
+
+    class Meta:
+        unique_together = ('item', 'current')
+
+    def __str__(self):
+        return "{}, current={}".format(self.item.uid, self.current)
+
+
+class CollectionItemChunk(models.Model):
+    uid = models.CharField(db_index=True, blank=False, null=False,
+                           max_length=44, validators=[UidValidator])
+    itemSnapshot = models.ForeignKey(CollectionItemSnapshot, related_name='chunks', null=True, on_delete=models.SET_NULL)
+    order = models.CharField(max_length=100, blank=False, null=False)
+
+    class Meta:
+        # unique_together = ('itemSnapshot', 'order') # Currently off because we set the item snapshot to null on deletion
+        ordering = ['order']
+
+    def __str__(self):
+        return self.uid